Causes of Enlarged Sternal Bursas (Breast Blisters)

Abstract

Bursas were taken weekly as normal turkeys developed from 3 to 22 weeks of age, and no specific bacterial or viral infection was found. Bacterial cultures were also made of condemned bursas taken at processing. Of 144 collected, 91% were sterile; the others had staphylococci, streptococci, or coliform organisms. Experiments with turkeys measured the effect of strain, body conformation, completeness of breast-feather cover, protection of the keel with sheepskins, age when put on range, and type of range on the incidence of enlarged sternal bursas. The strain difference of 25.4% breast blisters against 11.5% was highly significant (99% confidence). In one experiment the effect of feather cover was significant at the 95% level of confidence (61.7% breast blisters with no feather cover, versus 40% with complete feather cover). The effect of protecting the breast with sheepskin was significant at the 95% level of confidence in reducing incidence of breast blisters. There was no significant difference in the incidence of breast blisters in relation to body conformation, age, or type of range.

Prevalence of skin lesions in turkeys at slaughter

“…An enlarged sternal bursa (ESB), also called sternal bursitis or breast blister, corresponds to an enlarged keel with a fluid-containing swelling of the sternal bursa . In contrast to a previous study which classified ESB in three levels based on severity (Miner and Smart, 1975;St-Hilaire et al, 2003), we decided to use a binary mode, i.e. absence or presence of ESB.…”

“…One of the main methods for assessing animal welfare is based on the measurement of body lesions, as proposed in the Welfare Quality project for broilers and laying hens (Welfare Quality, 2009). In turkey production, some of these body lesions have been studied previously as footpad dermatitis (Martland, 1984;Ekstrand and Algers, 1997;Clark et al, 2002;Mayne, 2005;Hocking et al, 2008;Youssef et al, 2010;Krautwald-Junghanns et al, 2011), other leg and foot abnormities (Swarbrick, 1966;Nestor, 1971;Buffington et al, 1975;Krautwald-Junghanns et al, 2011) and breast lesions (Miner and Smart, 1975;Gonder and Barnes, 1987;Kamyab, 2001;St-Hilaire et al, 2003;Mitterer-Istyagin et al, 2011). As proposed in previous studies, these recordings may be carried out at the farm or at the slaughterhouse (Hocking et al, 2008).…”

“…Breast buttons were more frequent, with an average of 30Á1%, irrespective of severity, which is in line with the literature estimates of 22Á6% (St-Hilaire et al, 2003) and 27Á1% . A previous review (Kamyab, 2001) reported that the development of these breast lesions could be due to various factors: sex (Gonder and Barnes, 1987;Mitterer-Istyagin et al, 2011), genotype (Miner and Smart, 1975;Tilley et al, 1996), body weight (Kamyab, 1997), stress (Kamyab, 2001), photoperiod (Newberry, 1992) and flock management such as litter type (Tilley et al, 1996;Kamyab, 2001).…”

The pathology of the avian integument: A review

“…Enlargement of the sternal bursa (ESB) in chickens and turkeys occurs primarily from continual irritation due to pressure or friction on the anterior keel (Miner and Smart, 1975). Development of ESB is, however, influenced by sex (males greater than females), strain of bird {e.g.…”

“…Development of ESB is, however, influenced by sex (males greater than females), strain of bird {e.g. lighter breeds develop fewer ESBs), conformation, amount and completeness of feather cover over the bursa, growth rate and management practices, particularly those related to floor type and hardness (Miner and Smart, 1975). In chickens and turkeys, ESBs usually develop from 9 to 12 weeks and 11 weeks onwards, respectively.…”